JANUARY often feels like a dead loss when you’re itching to get down to some proper gardening but it’s the perfect time to sow seeds that need to experience a cold spell before they will germinate.

January is the perfect time to sow seeds that need to experience a cold spell before they will germi

In practice that means hardy trees and shrubs, alpines and wild flowers.

You’ll find a small selection of these on the seed racks at most large garden centres – either as individual varieties, or mixtures.

Don’t be put off if the only tree seeds you can find are labelled “bonsai plants”.

GETTY

Sow your seeds as soon as possible, while the weather stays cold

They will grow into bonsai specimens only if you train them deliberately, otherwise they turn into normal trees.

For the biggest range you’ll need to order seeds by post. Specialist firms such as Chiltern Seeds and Plant World stock a wide range of items you don’t find in the catalogues of big seed firms and Suffolk Herbs has a good range of wild flower seeds.

Sow your seeds as soon as possible, while the weather stays cold. Don’t wait until spring.

Use wide, shallow pots and put a good handful of coarse drainage material in the bottom – gravel or bits of broken clay flower pot are ideal, but some people use bits of broken polystyrene packaging.

GETTY

Suffolk Herbs has a good range of wild flower seeds that can be mailed

Now mix up some gritty free-draining compost from equal parts of John Innes seed compost, peat-free multipurpose compost and sharp sand or potting grit.

Half-fill the pots with this, then space the seeds out evenly over the top. Finally, cover the seeds with a very thin layer of coarse grit or even gravel.

I know it might sound crazy but small stones hold the seeds down and maintain humidity round them without cutting out the light.

They also provide good surface drainage, which discourages moss and algae from growing over the compost and smothering slow-growing seeds and seedlings.

Water well, using a fine rose on a watering can, then leave your pots of seed somewhere safe where it’s cold. You could stand them in an unheated greenhouse or cold frame, or sink them almost to their rims in the ground after covering the tops with cling film for protection.

GETTY

Seeds grow into bonsai specimens only if you train them deliberately

Don’t expect quick results. Some species will start coming up in spring but others take far longer – sometimes a good 18 months. But keep an eye on them.

Once the first small seedlings appear, move those pots on to a cool windowsill indoors or into a greenhouse or cold frame so they grow in comfort.

When they are big enough, prick them out in the usual way into small, individual pots. Growing hardy plants from seed is not as much effort as it sounds.

It’s very satisfying and it’s a great way of building up a good collection on the cheap.

Whichever way you look at it, being your own nurseryman is very rewarding.